Lithium ion batteries used in various industrial fields including various electronic devices employ lithium metal salts containing manganese, nickel and cobalt as positive electrode active materials. Recently, with an increased amount of lithium ion batteries to be used and expansion of the range of use, an amount of the lithium ion batteries to be discarded has been increased due to product life of the batteries and defects in the manufacturing processes.
Under such circumstances, there is a need for easily recovering expensive elements such as nickel and cobalt as stated above from a large amount of lithium ion battery scrap with a relatively low cost in order to reuse the elements.
In order to process the lithium ion battery scrap for recovering the valuable metals, the lithium ion battery scrap in the form of powder or particle obtained through each step such as roasting, crushing and sieving as required are firstly acid-leached using hydrogen peroxide water and lithium, nickel, cobalt, manganese, iron, copper, aluminum or the like that can be contained therein are dissolved in the solution to obtain a leached solution.
The leached solution is then subjected to a solvent extraction method to sequentially separate respective metal elements. In this case, the leached solution is sequentially subjected to a plurality of stages of solvent extraction or neutralization depending on the metals to be separated and each solution obtained in each stage is subjected to stripping, electrolysis, carbonization or other treatments, in order to separate each metal leached in the leached solution. More particularly, each valuable metal can be recovered by firstly recovering iron and aluminum, subsequently recovering manganese and copper, then cobalt, and then nickel, and finally leaving lithium in the aqueous phase.